论文标题
21厘米模拟的最小尺寸
Minimum size of 21-cm simulations
论文作者
论文摘要
宇宙21厘米的干涉法将彻底改变我们对电离时代（EOR）和宇宙黎明（CD）的理解。但是，该信号在大量尺度上具有结构，需要大型模拟框才能统计捕获相关字段。在这项工作中，我们量化了模拟宇宙21cm信号的功率谱（PS）的最小框尺寸。对于一系列盒子尺寸，我们对初始条件进行多个实现。我们根据对框长度1.1 GPC的模拟观察进行了量化收敛性，并用SKA1-LOW计算了1000H观察的热噪声。我们发现，框长度200-300 MPC的模拟低估了CD期间的大规模功率平均约7-9％。我们得出的结论是，需要$ l \ gtrsim250 $ mpc的盒长度在总噪声的<〜1 $σ$的水平上收敛。
Cosmic 21cm interferometry is set to revolutionize our understanding of the Epoch of Reionization (EoR) and the Cosmic Dawn (CD). However, the signal has structure on a huge range of scales, requiring large simulation boxes to statistically capture the relevant fields. In this work we quantify the minimum box size for simulating the power spectrum (PS) of the cosmic 21cm signal. We perform multiple realizations of the initial conditions, for a range of box sizes. We quantify convergence with respect to a mock observation of box length 1.1 Gpc, with thermal noise computed for a 1000h observation with SKA1-low. We find that simulations of box lengths 200-300 Mpc underestimate the large-scale power during the CD by ~7-9 % on average. We conclude that box lengths of $L\gtrsim250$ Mpc are needed to converge at the level of <~1$σ$ of the total noise.
